[passivate]

This problem ideally should be solved by the application creating them. So for e.g. You can use track-changes in MS Office, save work in multiple layers in Photoshop, etc.

Like the other poster I too believe that most binary files cannot be "versioned" (in that you cannot inspect their state and detect semantic changes). The only thing you can do is make a lot of copies - which makes the problem worse (IMO) because you can't diff them, or merge changes, or really do anything meaningful with them. You can do a 'human diff' by opening them side by side, but thats about it.